Technical Field
The present invention relates to a film formation device and method for forming a film of metal coating on a surface of a base material, particularly to a metal coating film formation device and method whereby a film of metal coating can be formed in a preferred manner by applying a voltage between an anode and the base material.
Background Art
Conventionally, a film of metal coating may be formed by causing metal ion deposition on the surface of a base material. Examples of such metal coating film formation technology that have been proposed include a plating process for metal coating film formation, such as electroless plating process, and a PVD method for metal coating film formation, such as sputtering.
However, when a plating process such as electroless plating process is performed, washing is required after the plating process, and waste liquid after the washing needs to be treated. When a PVD method such as sputtering is used for film formation on the base material surface, internal stress develops in the metal coating, limiting the extent to which the film thickness can be increased. Particularly, in the case of sputtering, film formation is only possible in high vacuum.
In view of the above circumstance, a metal coating film formation device has been proposed which is provided with, for example, an anode; a solid electrolyte film disposed between the anode and a base material (cathode); and a power supply unit for applying a voltage between the anode and the cathode (base material) (see Patent Document 1, for example).
In the film formation device according to Patent Document 1, the anode comprises a porous material that admits the passage of a solution containing metal ion (metal solution) and that supplies the solid electrolyte film with the metal ion. The porous material of the anode includes a porous base material that is insoluble to the metal solution and that is coated with a metal plated film comprising the same metal as the metal coating.
At a position on the opposite side from the base material and facing the anode, a plating anode is disposed via the metal solution which comprises the same metal as the metal coating. To the plating anode and the anode, a plating power supply unit is connected for causing the metal of the plating anode to be deposited on the anode surface via the metal solution.
In the film formation device, the solid electrolyte film is placed in contact with the base material surface, and a voltage is applied between the porous anode and the cathode (base material) by the power supply unit so as to dissolve the metal plated film on the anode. Metal ion from the dissolved metal plated film passes through the solid electrolyte film and is reduced and deposited on the base material surface, whereby a metal coating film can be formed on the base material surface. Even when the metal in the metal plated film is consumed during film formation, the consumed metal can be replenished from the metal of the plating anode by activating the metal the plating power supply unit.